ZrN的力学和热力学性质的第一性原理

利用基于密度泛函理论的赝势平面波方法，研究了fcc-ZrN的平衡态性质、不同压力下的弹性性质及热力学性质.通过对焓压关系、弹性性质的分析，推测fcc结构到bcc结构ZrN的相变发生在208~220GPa之间.进一步分析了fcc-ZrN在不同压力下力学的各向异性，得到了压力对ZrN力学性质的影响关系.计算分析了fcc-ZrN的热力学性质.研究结果表明:力学各向同性随压力增大明显减弱；一定温度下，热容随压力增加而减小；德拜温度随着压力增加而增大；低压区温度影响较大，高压区压力影响较大.

First Principles of Mechanical and Thermodynamic Properties for ZrN

The equilibrium properties， elastic and thermodynamic properties of fcc ZrN under different pressures were studied by using the plane wave pseudo potential method based on density functional theory (DFT). It was inferred that the structural phase transition of ZrN from fcc structure to bcc structure occurs between 208 to 220GPa by analyzing the relations of enthalpy and elastic property with pressure. The anisotropy of mechanical properties under different pressure was further studied to get the relation between the pressure and mechanical properties of ZrN. The thermodynamic properties of fcc ZrN were calculated. The results showed that the mechanical isotropy decreases significantly with increasing pressure. The heat capacity decreases with increasing pressure at certain temperature. The Debye temperature increases with pressure. The temperature plays the main role in the low pressure zone， and the pressure in the high pressure zone.